Abstract : This publication documents the derivation of geoacoustic models for the Straits of Sicily and Sardinia-Tunisia. The geologic description of the region is based upon published geological/geophysical papers and archive data. The zone of primary concern is the first few hundred meters below the sea floor, which, in the present case, consists of unlithified Quaternary-Pliocene sediments. Lying below this upper layer is acoustic basement, which consists of Miocene chalks and limestones or evaporities. The modeling procedures developed by E. L. Hamilton were then used to estimate the physical properties of these sediment types. Finally, bottom loss as a function of grazing angle at a variety of frequencies was computed for the sea floor models. (Author)